A vertical display mode is one of the display modes of a liquid crystal display (LCD). In the vertical display mode, the liquid crystals will present different alignments when viewed from different viewing angles, resulting in color distortion under large viewing angle. At present, in conventional liquid crystal displays adopting the vertical display mode, the pixel electrode therein is divided into four regions.
Moreover, in order to reduce the color distortion under large viewing angle, the liquid crystal pixel is also divided into two parts, so that eight regions are formed. One part of the regions is a main area, and the other is a subarea. The distortion under large viewing angle can be reduced by controlling the voltages of the two parts, which is called low color cast design.
FIG. 1 shows an equivalent circuit of a common pixel unit adopting the low color cast design. A pixel unit is divided into a main area and a subarea. Two or more different thin film transistors are utilized to supply power for the main area and the subarea of the pixel unit. When a scan line 11 is activated, the thin film transistor Tmain in the main area and the thin film transistor Tsub in the subarea will be turned on, so that electrical signals from a data line 13 are transmitted to a liquid crystal capacitor and a storage capacitor in the main area and the subarea of the pixel unit respectively. When the scan line 11 is deactivated and a charge sharing line 12 is activated, a shared thin film transistor Tcs is turned on, and part of voltage in the liquid crystal capacitor Clcsub and the storage capacitor CSTsub in the subarea is released into a shared capacitor Cb. In this way, a potential difference is presented between the main area and the subarea of the pixel unit, so that the color cast can be reduced with the aid of control.
However, in the low color cast design of the prior art, the pixel is divided into two parts, resulting in a reduced aperture ratio inevitably. In addition, the effective potential of liquid crystal in the main area is reduced, resulting in the loss of brightness in the main area. Consequently, the light transmittance of the liquid crystal display is negatively influenced.
In order to improve the display effect of the liquid crystal display, the present disclosure provides a new low color cast design scheme, which can be used to replace or combine with the low color cast design in the prior art.